Dobby mechanism of looms for weaving



July 15, 1930.

J. HEATLEY ET AL DOBBY MECHANISM OF LOOMS FOR WEAVING Filed March 23,1928 Patented July 15, 1930 BOBBY iunonrimsiu or M FF EYL I HEATLEY, orBLACKBURN, 1 ENGLAND LOOMS non WEAVING Application filed March 1928,Serial No. 264,183, and in Great Britain Mara 1927i This inventionrelates to improvements in or in connection with dobby mechanism of theKeighley type such as shown in British Patent .1692 of 1867toHattersley, et al., em-

ployed with looms for weaving, in which double-armed swing levers havepivoted to hem catches acting inconjunction with knives andjackleversare coupled to such swing levers. r

it is of course well known to pivot the jack lever at a point above,below or toone side of the pivot of one of the catches with the swingleverr 1 Our invention has particular reference to the type ofdobby'mechanism descrihed in British Patent No. 201,595 of which onsetthe present applicants, John Heatley, is a patentee, and consists inarrangingthe' pivctal pointof the. jack levers on a centre lineco-incidcnt with'that of the lower centre line or pivotal point of thelower series of catches instead on 'diilerent centres such as is shownin. the drawings of the aforesaid patcnt and such as iscommon practicein other :15 dohby mechanism of a similar kind and to so arrangeco-acting surfaces betweenthe jack lever and the double-armed swinglever as to act in mutual supportwhen' the doublearnied swinglever isbeingpulled forward to by its upper catch and whilst being returnedto'the initial position against the usual fixed stop for the wholeseries of doublearmed swing levers and jack levers.

Our invention will be fully described with reference to the accompanyingdrawing which shows a side elevation of one set of a double-armed swinglever, jack lever, upper and lower catches, pivoted arms co-acting withthe free ends of the latter'and the knives to for operating the catches,such parts being suiiicient of the mechanism of the dobby to enable theapplicationof our invention thereto to be understood.

In the aforesaid'drawing 1 indicates the double-armedswing lever havingan upper arm 2 to which theupper catch 3 is pivoted at 4- and a lowerarm Jtowhich the lower catch 5 is pivoted at 6 whilst? is the jack leverhaving an upper arm 8 pivoted to the 50 double-armed swing lever at 9and a lower arm 10, the outer endwhich is coupled to the heald eitherdirect or in any other usual way. ll-are the pivoted arms operatedby theusual pattern mechanism and co-acting with the catches ojand 5 whilst 13are the usual knives co-acting with the'catches in the well known way.Hitherto the pivotal centre of each jack lever hasbeen located somedistanceaway from the" pivotal centre. of the lower catch with thelowerarm of the double-armed swing lever -1. Instead of this the main featureof our present invention consists in arranging the pivotal point of.each vjack lever ona horizontal centre line co-i'ncident with the lowerhorizontal centre to line-or pivotal point of each lower catch and thelower arm of the double-armed swing lever. Tothis end we arrange thecross stay 1 1 running from one side "frame of the dobby to the othertoconstitute a fulcrum or support about which the jack levers may move,"such stay being preferablyof substantially crescent form in section andhaving an outer face lo'corresponding totheinner face of. thejack'leve'r." The-lower arm'5 of the I double-armed lever 1-is crankedbackwardly' to pass underthe hollow face of the'stay 14:, the end of the"cranked portion having pivoted to it the'rearward end of the'lowercatch 5 on'a centre line from which is struck 21:)

the outer curve of the stay 14, thus making the two centers, i. e'.,those of the jack lever and of the lower catch and lower arm of thelever, coincident. The lower catchmay be pivoted to the lower armofthelever 1 in any suitable manner permitting of the required freemovement oi the catch a-boutthe'centre It will'theretore be understoodthat when the upper catch is in engagement withthe upper knife thedouble-armed swing lever 1 and the jack lever 7 move simultaneouslyabout the I same centre with little or no friction between the pivotalcent-re ol the lower catch and the lower arm of the lever 1. The sameaction 7 occurs on the backward motion of theleve'r s5 1. The'bossorrear end of the lower catch is quite clear otthe inner face of thestaycr pivotal centre 14;, 1 c j In the dobby .mechanismshown in thedrawings of the aforementioned patent the 100 .constituting ourinvention.

In order that the jack lever 7 shall keep in contact with thedouble-armed swing lever 1 during the forward and backward movements ofthe upper arm of the lever due to the action of the upper catch, it isprovided with a projecting side face 16 which bears against a flange 16on the rear of the lower arm 5 about midway between the pivotal centreof the lower catch and the pivotal centre 9 of the jack lever and theswing lever.- This side face 16 acts as a stop for the lower arm 5 ofthe swing lever 1 on the completion of the backward motion of such lowerarm afterthe lower catch has been released from the lower knife. Duringoperation of the double-armed swing lever by the lower catch, The upperend of such lever bears against the usual stationary bar 28 (which actsas a fulcrum) arranged across the dobby against which the upper arms ofthe swing levers 1 may normally rest. A roller 26 as referred to in theaforementioned patent may also be employed as a fulcrum for the purpose.

t The face 16, formed upon the jack lever 7,

is in contact with the double-armed swing lever 1 at all times exceptwhen the lower catch 5? operates upon the double-armed swing lever 1.When the jack lever 7 is at rest as shown in the drawing neither of thecatches 3 or 5 being engaged bytheir respective draw-knives 13 it issupported by the combined cross stay and fulcrum 14c and also by thejoint or fulcrum 9 of the swing lever 1. The swing lever 1 is enabled tosupport lever 7 at the joint or fulcrum 9 by means of the face 16 oflever 7 and by the cross bar 28 against which itrests.

Assuming the jack lever to be at rest as shown in the drawin if the to")catch is drawn forward by its knife 13 the swing lever 1 null beprevented from turning upon its fulcrum 9 by the projection 16 upon theface of jack lever 7 and the swing lever 1 will, along with the jacklever 7, turn or partly revolve about the fulcrum 6 upon the crescentshaped bar 1 1. Again assuming the jack lever to be at rest as shown inthe drawing, if the bottom catch is drawn forwardvby its knife, theswing lever in turning upon the fulcrum 9 will heel'against the topcross bar 28 and the jack lever will again turn or partly revolve aboutthe fulcrum 6 upon the crescent shaped bar 14:. If thecatches areoperated al ernately the fulcrum 9 will be kept in its forward or drawnout-position, the swing lever will oscillate upon its fulcrum 9 and thejack lever will be retained in its lifted positionj More than onestopmember may be provided between the swing lever 1 and the jack lever 7 asshown on the drawing at 16, 16*, A, B and C, All that is needed, is thatthe swing lever 1 shall only be able to turn from its normal position(that is, the position shown in the drawing in which neither of thecatches has been operated to move the swing lever), by moving upon thefulcrum 9 of the lever 7 in'one direction, that is, in the direction asit may be operated by the bottom catch. Vhen operated by the top catchonly, the swing lever cannot turn upon its fulcrum 9 being prevented bythe stop or stops referred to, itand the jack lever 7 moving together asthough in one piece. I

' It will be understood that the invention is not limited solely to theform of construction shown, but that it may be modified in many wayswithin the scope of the appended claims. The arrangement hereinbeforedescribed enables the dobby generally to be less in height and less inlength, in proportion to the dimensions of swing lever l in the lattercase when shorter jack leversare employed to get the same lift on thehealds as with the ordinary longer jack levers, whilst at the same timemaking for easier movement of the mechanism.

We declare that what we claim is 2- 1. A dobby mechanism for dobbies ofthe Keighley type comprising in combination.

double arm swing levers, catches pivoted to said swing levers and jacklevers pivoted on an axis coincident with the pivot of one of saidcatches. v

2. A dobbymechanism for dobbies of the Keighley type comprising'incombination double arm swing levers, catches pivoted to said swinglevers and jack levers pivoted on an axis coincident with the pivot ofone of said catches, and a fixed pivotal support for the pivot forsaidjack levers of crescent shape cross section to permit one end of the1 swing lever to pass into it.

3. A dobby mechanism for dobbies of the Keighley type comprising incombination double arm swing levers, catches pivoted to said swinglevers and jack levers pivoted in an axis coincident with the pivot ofone of said catches, and an abutment projecting from each jack leveradapted to engage the double arm swing lever, so that the jacks anddouble arm swing levers move together under the action of the usualcatches and knives at all times except when the lower catches operateupon the double arm swing levers.

In witness whereof, we have hereunto signed our names this 8th day ofMarch, 1928. JOHN HEATLEY.

HAROLD ROGERS HEATLEY;

